I seal my egg tubs with Glad Press 'N Seal, so I open each egg tub about once a week to allow a little air exchange and to wipe off any condensation that's on the Press 'N Seal. I usually try and tilt the egg box a little by placing something underneath it on one end so that most of the condensation runs down the side of the tub and not onto the eggs, but there tends to be a little bit that doesn't run down the side.